Alcohol use influences the health status of individuals and may modify the natural history of infectious disease processes. Our goal is to elucidate the epidemiologic relationship between alcohol consumption and HIV/AIDS by utilizing existing HIV/AIDS data from the Women and Infants Transmission study (WITS), a population-based study of HIV-infected women and their infants. The specific hypothesis is that alcohol consumption accelerates the progression of HIV infection and affects pregnancy outcomes among HIV-infected women. We based the hypothesis on the observation that 1) alcohol intake increases in vitro and in vivo replication of HIV-1, 2) alcohol intake causes immunologic aberrations that share similarities to HIV-1 infection, and 3) alcohol use hinders medication adherence, which potentiates the emergence of drug-resistant HIV-I. Based on these observations, the focus of this proposal is to determine the consequences of alcohol consumption among HIV-infected women. The specific aims are to: 1. Examine the influence of alcohol consumption on clinical, virological, and immunological markers of HIV disease progression. We will develop propensity scores for alcohol consumption to give the likelihood of consumption and to adjust for the selective nature of alcohol use. Various types of alcohol consumption will be considered, including binge drinking, and frequent drinking. Both linear models and threshold models will be explored. 2. Determine the relationship between alcohol consumption and adherence to antiretroviral medications and consequently patient outcomes. The effect of alcohol use as a key determinant of adherence to antiretroviral therapies is not well defined since previous findings did not consider alcohol intake as a primary exposure of interest. We will develop an index for medication non-adherence based on the number of missed doses; and to discern the influence of various types of alcohol consumption on non-adherence to antiretroviral therapies. 3. Determine whether alcohol use and in-utero exposure to antiretroviral therapy are associated with adverse pregnancy outcomes and whether there is evidence of interaction between these two exposures and specific pregnancy outcomes. Interest in this aim is inspired by our recent finding indicating the association of cell-associated virus with perinatal transmission of HIV-1 despite the use of combination antiretroviral therapies. We will characterize patterns of maternal alcohol consumption during first, second, and third trimesters; and examine the join1 effects of maternal alcohol use and antiretroviral therapies on pregnancy outcomes including mother. to-child transmission of HIV.